Light emitting diode (“LED”) light sources can be longer lasting and more energy efficient than incandescent light sources. As a result, LED's can be a suitable, and often desirable, replacement for incandescent light sources. LED light sources are generally Lambertian in nature. That is, LED light sources generally appear to have the same brightness from any viewing angle in the projection region. That is because, as the viewing angle of an observer changes with respect to the optic axis of the light source, the apparent size of the observed emission surface decreases by about the same fraction as the intensity of projected light. Because apparent brightness (or luminance) is a measure of power per of unit of projected source area, the apparent brightness appears to be the same to an observer in the projection region. The Lambertian nature of LED light sources means that they generally only emit light in a single direction (e.g., forward, away from the light emitting surface), or towards a single projection region. That is, outside of the projection region (e.g., rearward of the light emitting surface), the LED generally projects no light, or virtually no light, without the assistance a reflective device. Thus, attempts to provide additional directionality behind the LED typically results in unconventional looking bulbs.
In contrast, incandescent light sources are inherently non-directional. That is, incandescent light sources generally emit the same amount of light over a very wide range of angles. For example, incandescent light sources can emit light with essentially equal intensity in all directions (i.e., over 360°) in the horizontal plane of the light source. That is, the intensity of light projected from an incandescent light source is essentially the same in front of the light source, behind the light source, and on all sides of the light source. And even in a vertical plane, the intensity of light from an incandescent source can vary by less than 10% over an angular range of about 270°. Thus, incandescent bulbs located near a wall or ceiling emit a large fraction of their light onto the wall or ceiling, which results in high reflective losses. It would be thus be useful for a light source to provide the sustainability and efficiency of LED light sources having additional control over directionality of the emitted light.